1. Technical Field of the Invention
One aspect of the invention relates to calibration of electronic displays, and in particular, to methods and systems for the calibration of electronic displays utilizing a multicolor camera.
2. Description of the Related Art
Electronic displays, such as those used in cellular telephones, computers and tablets may exhibit a significant amount of variability in their tone-responses, color responses and backlight-modulation responses. This is mainly due to variability in characteristics of various optical components used in manufacturing of the displays including variability in spectral power distribution (SPD) of LED backlights.
Thus, it is typical to calibrate each electronic display that is manufactured on a manufacturing line so that each display provides an accurate tone-response, color response and backlight-modulation response during use. Display characterization and calibration using a spectrometer or a color meter, however, can lead to two basic deficiencies. First, these color meters can only generate calibration data based on a single spot on the display (usually at panel center). Second, it generally takes a significant amount of time to do the required measurement because the display screen may need to be separately calibrated to have an accurate response for a plurality of different colors, whereas the calibration is only performed for one color at a time. For example, a Red/Green/Blue tone response for a liquid crystal display (LCD) may take up to 15 seconds per digital input level using a Photo Research PR-655 spectrometer, which only measures one wavelength of light at a time. The entire calibration process for a single display may take up to a total of about 48 minutes for a 6-bit per channel LCD display that needs to be evaluated and calibrated based on 192 test patterns of different shapes and colors.